Nitzschia seriata , Cleve, 32 1883, p. 478. 



Pinnularia lanceolata , Heiden and Kolbe, 2 ^ 1928, p. 598. 



Pleurosigma directum, Grunow, 33 1880, p. 53. 

 Occurs seldom in the plankton. 



Rhizosolenia alata, Brightwell, 34 1858, p. 96. 



Rhizosolenia alata f. indica (Peragallo), Hustedt, 3 ^ 1929, 

 p. 602. 



Rhizosolenia alata f. inermis (Castracane), Hustedt, 3 -' 1929, 

 p. 602. 



Rhizosolenia antarctica , Karsten, 1* 1905, p. 95. 



Rhizosolenia bidens, Karsten,! 1 1905, p. 98. 



This form has markings similar to R. styliformis , but 

 possesses a bifurcate spine. Heiden and Kolbe,29 1928, 

 p. 517, have made it a form of R. styliformis. The diatom 

 does not occur very frequently in the HIGHJUMP collection 

 and the author has not been able to form any opinion as to 

 its status. 



Rhizosolenia delicatula , Cleve, 36 1900, p. 28. 



Rhizosolenia hebetata f. semis pina (Hensen), Gran, 3 ' 1905, 

 p. 55. 

 A very variable form especially regarding size. 



Rhizosolenia styliformis , Brightwell, 3 * 1858, p. 95. 



Rhizosolenia styliformis var. longispina, Hustedt in Schmidt, 23 

 1914, plate 316, figs. 5-7, 12. 



Schimperiella antarctica , Karsten, 1905, p. 88. 



The genus Schimperiella is confined to the Antarctica. 



Synedra pelagica , Hendy, 1937, p. 335. 



This form is synonymous withS. spathulata , Schimper ex 

 Karsten, 11 1905, p. 124 but not s". spathulata , O'Meara, 38 

 1875, p. 310. It is not uncommon in the plankton and often 

 occurs with S . longissima. 



76 



